Integral barrel lock and extractor



Aug. 5, 1958 E. P. SIMMONS INTEGRAL BARREL LOCK AND EXTRACTOR 2Sheets-Sheet 1 Filed Dec. 2. 1954 A ffn/weya.

Aug. 5, 1958 E. P. SIMMONS 2,845,740

INTEGRAL BARREL LOCK AND EXTRACTOR Filed Dec. 2. 1954 2 Sheets-Sheet 2 EW [mi INVENTOR. [mwf x? Jim/2mm BY Affa/weyx x3 wwww 3 Q ww svwetfectzon the ejection action of the gun.

United States Patent" 2,845,740 INTEGRAL BARREL LOCK AND EXTRACTORErnest P. Simmons, Kansas City, Kans., assignor to Olin ,MathiesonChemical Corporation, a corporation of December'2, 1954, Serial No.472,633

- Application 2 Claim or. 42-75 iThisinvention relates to new and usefulimprovements in automatic shotguns, and has particular reference to asafety device preventing the removal of the barrel of an automaticshotgun of the split-chamber type when there is a shell in firingposition in the chamber.

' f'In automatic shotguns of the split-chamber type, the chamber,instead of being formed in the breech end of-the barrel itself, isformed in a separate chamber member carried by the receiver. Thischamber member, when the gun is in firing position, is locked into thereceiver by means entirely independent from the connection of the barrelinto the receiver. Thus when vin the ordinary dismantling of the gun forstorage the barrel is detached from the receiver, it is entirelypossible that a shell may be left in the chamber in position for firing.This is of course extremelydangerous, in that the gunmay subsequently beaccidentally discharged by I jarring or by careless handling duringstorage, or when next reassembling' the gun.

The prime object of this invention is the provision of a very simpleandeconomical means which absolutely prevents this occurrence, andswhich requires thatthe shell in the chamber be removed,

or at least that the bolt be moved to a-non fiiing'position, beforethe'barrel can be detached from the receiver.

This object is accomplished in general by'the provision of a lockingmember attached to the bolt of the gun and projecting forwardlysufiiciently far, when the bolt is closed for firing, to engage in anotch formed in the breech end of the barrel. The barrel'is thus lockedagainst rotation, andthereby against removal from-the receiver, sincethis removal requires at least a partial rotation of the barrel. Whenthe bolt isretracted man-' ually, thelockingmember is withdrawn from thebarrel notch and the barrel may be removed, but at the same a are of thebayonet type, only the opposite quadrants v the forward'end of saidtube.

prevented from rotating by a connection thereof, not ,7 shown, to tube24, such as a radial arm fixed to the barthe barrel.

extension 36 having the "form generally of a downwardly openingsemi-cylinder. The rearwardjend of said ex tension terminates in spacedrelation to a forwardly facing where thegunners stand abreast, andshells ejected from one vshooters gun often strike adjacent shooters.

Other objects. are simplicity and economy ofconstruction,.efliciencyanddependability of operation,'and adaptability to be incorporated inpro-existing guns with a minimum amount of alteration.

With these objects in view, as well as other objects whichwill appear incourse of the specification, reference will. be had to the drawing,wherein:

Fig. 1 is a longitudinal.mid-sectional view of the re-- ceiver andadjacent portions of anautomatic shotgun embodying the, presentinvention, with parts left in elevation. Fig. 2 is a fragmentaryviewsimilar to-Fig; 1, with additional parts. left in elevation. 1

the rearward end of the shell in the'chamber, as shown Fig. 3 is aslightly irregular sectional view taken on line III.III of Fig. 1, withparts left in elevation.

Fig. 4 is a sectional view taken on line IV-IV of Fig. 1. s Fig. 5 is asectional view taken on with parts left in elevation.

Fig. 6 is a sectional view taken on line VIVI of Fig. 2, with partsleftin elevation.

Like reference numerals apply to similar parts through: 1 out theseveral views, and the numeral 2 applies -to the receiver portion of anautomatic shotgun of the split: chamber type, said receiver being hollowand elongated longitudinally of the gun and having right and left sidewalls 4 and 6, top wall 8, front wall 10, rear wall 12,

and being open at the bottom. The rearward portion of the bottom openingis closed by a trigger frame 14 held in the receiver by an assembly pin16. The forward portion of the bottom opening is occupied by a shellcarrier 18 carried movably by frame 14. Said shell carrier forms no partof the present invention, but its function will be described generallybelow.

The. gun barrel 20 is threaded into a bore 22 formed through the frontwall 10 of the receiver, and communicates with the interior of thereceiver. The threads of this connection may be standard, but morecommonly of the barrel and bore 22 being threaded, as indicated in Fig,6. In assembling, the barrel threads maybe insertedaxially to their fulldepth into the receiver bore 22, and the barrel then rotated deg."t obring the' A magazine tube 24 is dis posed beneathiand parallel to thebarrel, and is also.

threads into engagement.

threaded at its rearward end into front wall 10 ofthe receiver incommunicating relation with the interior of Shells 26 carried in saidmagazine tube said receiver. are urged rearwardly by a spring, notshown, carried in The barrel is normally rel and detachably connected totube 24.

Carried for longitudinal sliding movement in the 'rear- 1 ward endportion of the barrel isa tubular shell chamber 28 adapted to receive ashell 26 therein as best shown-in Figs. 1 and 3. .Said chamber isprovided at its rearward end withan internal shoulder 30 against whichthe rim '32 of the shell abuts, and an external shoulder 34 whichnormallyabuts the rearward end of The chamber is provided with arearward shoulder 38 formed internally in-receiver 2. As best shown inFigs. 1 and 3, a pin 40 is carried slidably in a: bore 42 formed in thewall of said extension, and isv urged rearwardly against shoulder. 38 bya compression spring 44 carried in said bore. The chamber shoulder 34is'thus urged forwardly atall times toward engagement with the rearwardend of the barrel.

The bolt 46, when the gun-is closed, is disposed within chamberextension 36, the forwardend thereof abutting in Figs. 1 and 3. Adjacentits rearward end, said bolt is provided with an u'pwardly projecting lug48, which projects into a slot 50 formed in the upper wall of chamber 1extension 36, whereby to lock the bolt against rearward :rnovementrelative to the extension. The bolt is positively secured against anyfurther forward movement in the receiver by the engagement of adepending lug 52 (Fig. 1) integral with the bolt against the inner: face5 of the front wall 10 of the receiver. The mating surfacesof lug 48 andslot 50 are inclined whereby to pi'ovide a cam' action forcing the "boltfirmly forward againsttheff Patented .Aug. 5, .1958

line v-v of Fig. 1,

.a matching shoulder of the bolt.

shell when the'bolt is moved upwardly. The bolt carries'a firing pin 54therein. Said firing pin is urged rearwardly in said bolt against afstop pin 56 by a spring 58, sothat the forward end thereof is disposedrear-wardly of "the" forward end-of'the bolt, andth'e -rearwardendthereof projects rearwardly from the-back end of the bolt. is-urgedpivotally forwardly by spring 64 to strike the rearward end of thefiring pin to drive it forwardly to detonate the shell in the chamber inthe usual manner. Said'hammer is normally retained in its cockedposition by the engagement in a notch 66 thereof of the toe 68 of atrigger 70 pivoted in frame 14 at 72. When the trigger'is pulledrearwardly against the pressure of trigger spring 94, the toe thereof isdisengaged from the hammer notch 66, and the hammer'functions asdescribed.

Thebo'lt also carries an ejector pin 76 for longitudinal movement inapproximately parallel relation to but spaced transversely apart fromthe firing pin. The ejector pin is urged rearwardly in the bolt by aspring 78 carried in thebolt, whereby a shoulder 88 (Fig. 3) thereofengages In this position the Iorward end of the ejector pin is retractedwithin the bolt, and the rearward end projects outwardly from therearward end of the bolt.

The bolt also carries an extractor 82 comprising a generally L-shapedlever having one arm 84 pivoted in the bolt on a vertical pivot pin 86and projecting outwardly from said bolt transversely of the gun, as bestshown'in Fig. 3, and a right angled arm 88 extending forwardly along theside of the bolt to a point ahead of the forward end of the bolt. Theextractor arm 88 is urged resiliently toward the bolt by a spring 90carri'ed in-the bolt. Ann 88 extends forwardly through a notch 92 formedthrough the rim of the chamber 28 between shoulders 30 and 34 thereof.Said arm is provided at its forward end with a tooth 94 which engagesthe forward edge of the rim 32 of the shell in the charnber (Fig; 3).Extractor arm 88 is provided with a forward extension 96 which, when thebolt is closed, projects into a'notch 98 formed in the external surfaceof the rearward end of barrel 20. The function of the extractor andextractor extension will be fully described below.

The bolt is supported in the receiver by a horizontal pin 100 extendingtransversely of the gun and passing through a pair of matching slots 102formed in a pair of side walls 104 and 106 which are integral with anddepend from the bolt. The forward end portions of said slots, in whichpin 100 is disposed when the bolt is closed, are substantiallyhorizontal. The rearward portions of said slots are inclined upwardlyand rearwardly, for a purpose which will appear. Pin 100 extendsoutwardly from the sides of the bolt, and the ends thereof are mountedin slides 108 and 110. Said slides are mounted for forward and rearwardsliding movement respectively in grooves 112 and 114 formed in the innersurfaces of receiver walls 4 and 6 (Fig. 4). The right slide 108 isprovided with a thumb-piece 116 which projects outwardly through a slot118 formed in receiver wall 4, whereby said slide may be operatedmanually. Said slot is upwardly enlarged as at 120 to form an openingthrough which shells may be ejected.

A link 122 is pivoted on pin 100 between bolt side walls 104 and 106,and extends rearwardly through the receiver. Hammer 60 operates througha longitudinal slot 124 formed in said link. At its rearward end, saidlink is pivoted at 126 to an inertia rod 128 which is carried forlongitudinal sliding movement in a tubular extension 130 of thereceiver, said extension being disposed in the stock 132' of the gun. Arecoil spring, not shown, is disposed in tube 130 behind rod 128, andurges said rod forwardly.

The general operation of the gun is as follows: When thegun fired aspreviously described, the chamber A hammer 60 pivoted in triggerfrarne14 at 62 28, extension 36, and bolt 46 first recoils rearwardly as aunit against the pressure of spring loaded pin 40, since the bolt islocked in the chamber extension. The bolt motion is also transmittedthrough pin and link 122 to inertia rod 128, imparting substantialmomentum thereto. The rearward movement of the chamber is arrested aftera short travel by the engagement of the rearward end of extension 36with receiver shoulder 38, but inertia rod 128 continues rearwardly byits momentum, carrying pin 100 rearwardly in bolt slots 102. Whenpin-100 engages the inclined rearward portions of said slots, it camsthe rearward end of the boltdownwardly, lowering bolt lug 48 from theslot 50 of the chamber extension. The momentum of inertia rod 128 thencarries the bolt rearwardly independently of the chamber. During thismovement, the extractor tooth 94, which is in engagement with the rim 32of the expended shell in the chamber, pulls the shell out of the thereceiver, the rearward end of ejector pin 76 engages and is arrested byrear wall 12 of the receiver,-

thus forcing. said ejector forwardly with respect to the bolt, againstthe pressure of ejector spring 78, as the bolt continues its rearwardmovement. The forward end of the ejector pin is thus projected throughthe forward end of the bolt into engagement with the shell, therebypivotingit around extractor tooth'94 and throwing it outwardly throughejection opening 120 of the receiver. The bolt is then ready to startits forward movement under the urging of the recoil spring. During itsrearward movement a new shell 26 was ejected from the magazine tube 24by the magazine spring onto shell carrier 18. As the bolt startsitsforward movement, it engages a suitable mechanism (not shown) carried bytrigge'r frame 14 and operable to flip shell carrier 18 upwardly to movethe shell carried thereby into the path of the bolt. The bolt thencontinues forwardly to its locked position, pushingthe shell intochamber 28.

While the above description of operation is some what incompleteandsketchy, it is believed suflicient to illustrate the operation of thebarrel locking mechanism. It is apparent that when the bolt isclosed'and locked, as shown in Figs. 1 and 3, extension 96 of extractor82 is engaged in notch 98 of the barrel, thereby locking the barrelagainst rotation and preventing the removal thereof from the receiver.To remove the barrel, the operator must first pull thumb-piece 116rearwardly, thereby moving pin 100 and slides 108 and rearwardly,sufliciently far to cause pin 100 to cam the bolt downwardly tounlocklug 48 thereof from chamber extension slot 50'as previouslydescribed, and still further to move the bolt rearwardly with respect tothe chamber. The bolt movement pulls the extractor extension rearwardlyfrom barrel notch 98, and the barrel may then berotated and removed.

While only a short bolt movement is required to free the barrel, it iscontemplated that the operator, ifhe attempts to remove the barrel andfinds it locked, will be reminded-that there may be a live shell in thechamber and will hence pull the bolt back not only far enough to freethebarrel, but all the way back to eject the shell. However, if he doespull the bolt back only far enough to free the barrel and not far enoughto eject the shell, the-gun will still remain safe. When the barrel isremoved, the'chamber is urged forwardly by pin 40 and spring 44 to sucha'point that bolt lug 48 cannot enter slot 50 of the chamber extension,but strikes the inner extractor will afiect the normal ejection actionof the gun, since the shell as it is ejected strikes against theextension. Its efiect is to substantially reduce the distance the shellis thrown. This is considered an advantage particularly in matchshooting, wherein the gunners often stand abreast on a firing line andare quite often struck by shells ejected from the guns of those adjacentin line.

While I have shown and described a specific'embodiment of my invention,it will be readily apparent that many minor changes ofstructure andoperation could be made without departing from the spirit of theinvention as defined bythe scope of the appended claims.

What I claim as new and 'desireto protect by Letters Patent is:

1. In an automatic shotgun, a receiver, a barrel secured at is rearwardend in said receiver by a rotatably detachable connection, a tubularchamber disposed slidably in the rearward portionof the barrel andextending into the receiver, said chamber being operable to receive ashots-hell and having an internal shoulder for engaging the rim of theshell, said chamber shoulder being formed with a first notch, a boltslidably disposed within the 7 receiver, means operative to lock thebolt in a battery position in the extension of said chamber whereby theforward end of the bolt abuts the head of said shell, and

a locking member pivotally mounted to the bolt and received by saidfirst notch and extending forwardly to engage a second notch formed inthe rear end of i the barrel effective to lock the barrel to thechamber.

2. The structure set forth in claim 1 wherein the bolt carries apivotally mounted extractor comprising an arm secured to the bolt andextending forwardly therefrom past the edge of said shell rim and beingprovided with a tooth operable to engage said shell rim to extract theshell from the chamber when the bolt. is moved away from its batteryposition, said locking member comprising a forward extension of theextractor arm.

